Abstract: A disk braking device suppresses warp of friction members and deterioration in reaction at the time of braking, and provides friction members with a uniform service life, where pistons are increased in number to heighten a braking force. A piston mechanism comprises pistons arranged along an outer periphery of a disk plate. The pistons are allotted to a plurality of piston portions that have different cylinder areas s1 and (s2+s3). A pad unit is divided into a plurality of pad unit portions that have different total pressure contact areas p1 and (p2+p3) corresponding to the cylinder areas s1 and (s2+s3).

Abstract: A disk braking device for a motorcycle ensures radiation quality of a disk plate and reduces friction member abrasion of a friction member. A plurality of through-holes are formed in the disk plate and a plurality of notches are formed at peripheral edges of the disk plate. The through-holes are arranged so that one of the through-holes or less is disposed on a radial line extending from the center of the disk plate.

Abstract: A hydraulic pressure feeder suppresses wavy motions and bubbles in working oil in a reservoir tank. A hydraulic braking device includes a master cylinder mounted to a handle bar to accommodate therein a piston mechanism. A reservoir tank replenishes the piston mechanism with working oil. A brake lever is mounted to the master cylinder to drive the piston mechanism. The master cylinder is arranged forwardly of the handle bar and the reservoir tank is provided on the master cylinder to cover an upper portion of the master cylinder.

Abstract: A hydraulic pressure feeder suppresses wavy motions and bubbles in working oil in a reservoir tank. A hydraulic braking device includes a master cylinder mounted to a handle bar to accommodate therein a piston mechanism. A reservoir tank replenishes the piston mechanism with working oil. A brake lever is mounted to the master cylinder to drive the piston mechanism. The master cylinder is arranged forwardly of the handle bar and the reservoir tank is provided on the master cylinder to cover an upper portion of the master cylinder.

Abstract: A disk braking device for a motorcycle ensures radiation quality of a disk plate and reduces friction member abrasion of a friction member. A plurality of through-holes are formed in the disk plate and a plurality of notches are formed at peripheral edges of the disk plate. The through-holes are arranged so that one of the through-holes or less is disposed on a radial line extending from the center of the disk plate.

Abstract: A disk braking device suppresses warp of friction members and deterioration in reaction at the time of braking, and provides friction members with a uniform service life, where pistons are increased in number to heighten a braking force. A piston mechanism comprises pistons arranged along an outer periphery of a disk plate. The pistons are allotted to a plurality of piston portions that have different cylinder areas s1 and (s2+s3). A pad unit is divided into a plurality of pad unit portions that have different total pressure contact areas p1 and (p2+p3) corresponding to the cylinder areas s1 and (s2+s3).